Sugar coating apparatus

ABSTRACT

An apparatus for coating confectionary centers, medical tablets or similar articles, comprising a rotary drum, the internal space of which is divided into a plurality of chambers for receiving and holding separate batches of articles. The chambers are separated from one another by substantially diametrical partition walls that are moved axially through the drum so that the chambers travel in the same direction and preferably with increasing capacity or volume.

United States Patent 11 1 11 3,739,744 Eriksen June 19, 1973 1541 SUGAR COATING APPARATUS 3,285,223 11/1966 Sahlin 118/418 x 25,306 8/1959 Pratt 259/87 [76] 'f Erma, 570,360 10/1896 Acheson 259/86 x NZikSkOVVCJ, 2500 Valby, Denmark [22] Filed: June 14, 1971 Primary Examiner-John P. Mclntosh [2]] APPL 152,590 Attorney-Stevens, Davis, Miller & Mosher Foreign Application Priority Data June 22, 1970 Denmark 3218 US. Cl. 118/19, 118/20, 118/24,

Int. Cl. 1305c 9/00, A23g 3/26 Field of Search 118/19, 20, 418,

References Cited UNITED STATES PATENTS Clark et al. 259/87 X An apparatus for coating confectionary centers, medical tablets or similar articles, comprising a rotary drum, the internal space of which is divided into a plurality of chambers for receiving and holding separate batches of articles. The chambers are separated from one another by substantially diametrical partition walls that are moved axially through the drum so that the chambers travel in the same direction and preferably with increasing capacity or volume.

ABSTRACT 5 Claims, 3 Drawing Figures Pate nted June 19, 1973 2 Sheets-Sheet 1 Patented June 19, 1973 2 Shoots-Sheet 2 SUGAR COATING APPARATUS Coating of confectioneries and medical tablets is traditionally carried out in so-called coating pans comprising a rotary bowl or pot-shaped container, in which the articles or centers to becoated while being heated and usually also ventilated, are successively poured over with the coating material until each article is evenly covered by a layer of coating, usually sugar, of the desired thickness.

In larger production installations use is-oftenmade of a considerable number of such coating pans operated individually but treating partially the same material successively. This is effected in the manner that an empty coating pan isfilled with a suitable batch of articles, for example 50 kg, which corresponds to about half the volume of the container of the pan. When for example a quantity of 35 kg boiled sugar solution has been successively added, the capacity of the pan must be regarded as fully utilized, and part of the contents must therefore be discharged whereafter coating of the remainder, for example about 50 kg, may continue. The discharged part of the contents may, with a view to further coating, be filled into another pan with idle capacity, i.e., either an empty pan or a pan containing a smaller batch which has reached approximately the same step of the coating process. In this manner the total capacity of a plurality of coating pans available is fully utilized, but in return this requires a considerably amount of work in connection with'the transfer of the partially coated articles between the pans. This work is effected manually, and the same applies to the operation as such of the pans by adjusting various valves in conformity with the actual need. The invention has for its object to provide an automatically operating sugar coating apparatus, which even with a very high capacity, for example a capacity corresponding to that of a few hundred traditional coating pans, requires only a minimum-of-manual work,.and which affords the possibility of accurately controlling the entire coating process.

The coating apparatus according to the invention is characterized in that it comprises a drum journalled for rotation on its substantially horizontal axis and having at one end an inlet for the articles to be coated, a plurality of transversal partition walls which are movable through the drum from the inlet end thereof towards its other end and divide the drum space into a number of chambers for receiving separate batches of the articles to be coated and which are travelling in the axial direction of the drum, means for supplying preferably heated and dried ventilating air to the drum, and means for supplying coating material, for example sugar solution and dyestuff, in adjustable quantities to the various chambers of the drum.

In such apparatus each batch can be kept entirely separated from the other batches from the start to the end of the coating process, namely in one each of the rotary drum travelling chambers, and during the travelling motion the various batches may be supplied with coating material in adequate quantities totally as well as per time unit, just like the supply of ventilating air may be adapted to conditions, so that the coating process proceeds under optimum conditions. Control of the various functions, particularly the supply of coating material and air, may be effected fully automatically by means of conventional equipment, which may be built into the drum.

A particularly important embodiment of the sugar coating apparatus according to the invention is characterized in that the partition walls are movable through the drum at a continuously or stepwise increasing velocity. Through this measure it can'be ensured that the length and consequently the volume or capacity of the individual chambers increases gradually as the chambers travel through the drum and in time with the increase of-volume of the relevant batch. This means that the total'capacity of the apparatus may. at any time be fully utilized since it is not necessary to reserve space in the individual chambers for the increase ofvolume caused by the successively applied coating material;

The axial or lengthwise motion of the partition walls may be provided in different ways, for example pneumatically or hydraulically, but according to the invention it is preferable that the drum contains a stationary frame comprising one or more throughgoing guide rails for slidably supporting the partition walls and a plurality of endless chain drives disposed in successive and overlapping relationship and having catching means for moving the partition walls along the guide rails over one part section each. A stepwise increasing velocity of the motion may in this case be ensured by the chain drives, which pairwise, in their areas of a overlap, have a common shaft with fixed sprockets, the diameters of which are larger for a subsequent chain drive than for a preceding chain drive.

In this manner the apparatus will through structurally simple measures be capable of working more reliably with a minimum of inspection and maintenance. The size of the installation may be chosen according to need, but the drum may by way of example have a length of5 to 25 m and a diameter of l to 3 m or more.

The invention will now be more fully explained with reference to the diagrammatical drawing, in which FIG. 1 shows a complete installation comprising an embodiment of the apparatus of the invention,

FIG. 2 a cross-section on a larger scale through the rotary drum of the apparatus, and

FIG. 3 is a longitudinal section through the drum on a somewhat smaller scale and partially on the line III- -III in FIG. 2.

In FIG. 1, reference numeral 1 designates the coating drum of the apparatus which is disposed with a substantially horizontal axis and, by means, not shown, may be rotated on said axis. Connected to drum 1 is a pipe 2 through which coating material, usually boiled sugar solution, can be supplied by means of a pump 3 from a pair of storage containers 4, which may be coupled-in according to choice by means of valve 5. Storage containers 4 receive the material from an automatic boiler 6 and via a change-over valve 7. The material is supplied to boiler 6 by means of a pump 8 and via a change-over valve 9 from a pair of sugar-dissolvers 10.

Further, dyestuff can be supplied to drum 1 via a pipe 11 from a battery of dyestuff containers [2. The required pumps and regulating valves for controlling the supply of dyestuff are not shown in the drawing.

Dried and heated ventilating air flows through drum 1 in the main direction indicated by an arrow in FIG. 1. The consumed gaseous fluid, i.e., wetted air impurified by sugar dust, is discharged from drum 1 via a pipe 13 into a cyclone 14 in which the sugar dust is separated off to be returned to sugar dissolvers 10. A pipe extends from the top of cyclone 14 to the inlet of a centrifugal blower 16, which blows the air through a conditioning unit comprising a filter 17, a cooling section 18, in which the air is dried, and a heating section 19 from which a pipe 20 extends back to drum 1.

Extending through drum 1, see particularly FIG. 2, is a frame 21 which in the embodiment shown constitutes a grid structure with three parallel pipes 22, 23 and 24, of which pipe 23 is fragmentarily indicated in FIG. 3. The two pipes 23 and 24 serve for supporting and guiding a plurality of loose partition walls 25a, 25b, 25c and 25d, which by means of slide shoes 26 are slidably supported on the two pipes 23 and 24.

In FIG. 2 the direction of rotation of the drum is indicated by an arrow, and it will be seen that plates 25a etc. with their arced edges extend along more than half the drum periphery, but in such a way that the plates extend to a higher level at the side of the drum 1, where the drum wall moves upwards during the rotary motion, than at the other side of the drum. In this way the plates or partition walls 25a etc. will constitute a sufficiently effective separation between a plurality of chambers 27a, 27b etc. into which they divide drum 1, and at the same time the plates will leave sufficient space in the top left-hand quadrant of the drum section for frame 21 and the equipment supported thereon, namely a number of chain drives 28a, 28b etc., a pair of air injection and air suction pipes 35 and 36, which connect to pipe 20 and pipe 13, respectively (see FIG. 1) and a plurality of pipes 31, which connect to supply pipes 2 and 11 (FIG. 1) and are provided with spraying nozzles adequate in number and shape to discharge coating material and dyestuff in the desired quantities and with the desired distribution into rotary drum 1.

Inclined shafts 29a, 29b etc. are supported in suitable spaced-apart relationship on frame 21, of which shafts the first one supports a single pair of sprockets 30, whereas the other shafts are shown equipped with two pairs of sprockets 31a, 31b; 32a, 32b etc. The two pairs of sprockets and 31a form part of the chain drive 28a and support a pair of endless parallel driving chains comprising catching means 34, three such catching means being shown in FIG. 3. Further, the chains run on idlers 33, which over a part section force the chains to run along the supporting and guiding pipes 23 and 24 and at such distance from the edges of the plates with the slide shoes 26 as to keep the catching means 34 into engagement with the plates over said part section. The direction of travel of the chains is in FIG. 3 indicated by arrows, and it will be seen that a catch 34 at the left-hand idler 33 has just entered into engagement with plate 25a, whereas a catch 34 of the same chain drive has at the right-hand idler 33 just entered out of engagement with the next-following plate 25b subsequent to said plate having been taken over by a catch of chain drive 28b. Consequently it follows that plates 25a, 25b etc. are moved continuously through rotary drum 1 in the direction from the left to the right. Having passed through the entire drum the plates may be returned to the left-hand or inlet end of the drum for another run.

In FIG. 3 it is indicated that sprockets 30 and 31a have the same diameter, and the same applies to sprockets 31b and 32a etc., but at the same time it holds good that the b-sprockets have a larger diameter than the a-sprockets, which means that the partition wall 25 advanced by a subsequent chain drive is moved at a greater velocity than a partition wall 25 advanced by a preceding chain drive. Thus, the velocity of the plates increases stepwise during the travel through drum 1 and, consequently, the length of the chamber 27a, 27b, etc. defined by said partition plates will increase continuously, which has the advantage emphasized above, namely that the total capacity of the rotary drum can at any time be fully utilized.

What I claim is:

1. Article coating apparatus, comprising a drum mounted for rotation about its substantially horizontal axis and defining an article tumbling space, said drum having an inlet and a discharge opening for the articles, a plurality of movably supported partitions dividing said tumbling space into an axial series of individual chambers to hold separate batches of articles, means for moving said partitions parallel to said axis, said separate batches of articles being moved with said partitions, and means for supplying coating material and ventilating air in adjustable quantities to said chambers.

2. Article coating apparatus as claimed in claim 1, comprising means for moving said partitions from one end of said drum to the other end thereof at a stepwise increasing velocity.

3. Article coating apparatus, comprising a drum mounted for rotation about its substantially horizontal axis and defining an article tumbling space, said drum having an inlet and a discharge opening for the articles, a stationary frame structure extending through said drum from one end thereof to the other end, a plurality of partitions slidably supported by said stationary frame structure and dividing said tumbling space into an axial series of individual chambers to hold separate batches of articles, a plurality of endless chain drives disposed in successive and pairwise overlapping relationship, said chain drives having catching means for moving said partitions along said frame structure over individual longitudinal sections thereof, and means for supplying coating material and ventilating air in adjustable quantities to said chambers.

4. Article coating apparatus as claimed in claim 3, wherein said endless chain drives in their ares of overlap have a common shaft carrying at least one set of corotating sprockets belonging to a preceding and a subsequent chain drive, respectively, the diameter of the sprocket belonging to the subsequent chain drive being larger than that of the sprocket belonging to the preceding chain drive.

5. Article coating apparatus as claimed in claim 3, wherein said partitions have the shape of circular plates with a diameter that is substantially as large as that of said drum, and with a sector-shaped cut defined by a substantially horizontal edge pointing towards the descending side of said rotary drum and an upwardly inclined edge pointing towards the ascending side of the drum, said cut leaving a space within the drum for accommodating said frame structure.

# t i i l 

1. Article coating apparatus, comprising a drum mounted for rotation about its substantially horizontal axis and defining an article tumbling space, said drum having an inlet and a discharge opening for the articles, a plurality of movably supported partitions dividing said tumbling space into an axial series of individual chambers to hold separate batches of articles, means for moving said partitions parallel to said axis, said separate batches of articles being moved with said partitions, and means for supplying coating material and ventilating air in adjustable quantities to said chambers.
 2. Article coating apparatus as claimed in claim 1, comprising means for moving said partitions from one end of said drum to the other end thereof at a stepwise increasing velocity.
 3. Article coating apparatus, comprising a drum mounted for rotation about its substantially horizontal axis and defining an article tumbling space, said drum having an inlet and a discharge opening for the articles, a stationary frame structure extending through said drum from one end thereof to the other end, a plurality of partitions slidably supported by said stationary frame structure and dividing said tumbling space into an axial series of individual chambers to hold separate batches of articles, a plurality of endless chain drives disposed in successive and pairwise overlapping relationship, said chain drives having catching means for moving said partitions along said frame structure over individual longitudinal sections thereof, and means for supplying coating material and ventilating air in adjustable quantities to said chambers.
 4. Article coating apparatus as claimed in claim 3, wherein said endless chain drives in their ares of overlap have a common shaft carrying at least one set of co-rotating sprockets belonging to a preceding and a subsequent chain drive, respectively, the diameter of the sprocket belonging to the subsequent chain drive being larger than that of the sprocket belonging to the preceding chain drive.
 5. Article coating apparatus as claimed in claim 3, wherein said partitions have the shape of circular plates with a diameter that is substantially as large as that of said drum, and with a sector-shaped cut defined by a substantially horizontal edge pointing towards the descending side of said rotary drum and an upwardly inclined edge pointing towards the ascending side of the drum, said cut leaving a space within the drum for accommodating said frame structure. 